Furnaces

ABSTRACT

A static non-tipping electric induction furnace having a cover which extends over the upper end of the container in which metal to be melted is loaded, said cover comprising an outer casing lined with refractory material and having at one side thereof a charging door which slides between open and closed positions.

[ 1 Nov. 19, 1974 [56] References Cited UNITED STATES PATENTS 2,892,553 6/1959 Calderon............. 214/18 SC Primary Examiner-R. N. Envall, Jr. Attorney, Agent, or Firm-Baldwin, Wight & Brown [57] ABSTRACT A static non-tipping electric induction furnace having a cover which extends over the upper end of the container in which metal to be melted is loaded, said cover comprising an outer casing lined with refractory material and having at one side thereof a cha ing door which slides between open and closed positions.

14 Claims, 3 Drawing Figures Inventor: Reginald E. Laflin, Balcombe,

England A.P.V. Paralec Limited, Crawley, Sussex, England Dec. 13, 1973 [2]] App]. No.: 424,634

Foreign Application Priority Data Dec. 21, 1972 Great Britain..... 59066/72 13/26, 13/33, 214/18 R F27d 1/18 13/26, 27, 33, 31; 214/18 R, 18 SC United States Patent 1191 Laflln FURNACES [73] Assignee:

[22] Filed:

[52] US. [51] Int. [58] Field of Search nwmwm PATENHL 1 9W4 3,849,585 sum HP 3 FIG. I

PATENRU .J/ 1 91914 3 849. 58 5 SHEET .3 OF 3 FURNACES This invention relates to furnaces and is more particularly concerned with a static non-tipping electric induction furnace.

According to the present invention a static electric furnace has a cover which extends over the upper end of the container in which metal to be melted is loaded, said cover comprising an outer casing lined with refractory material and having at one side thereof a charging door which slides between open and closed positions.

Preferably the door when opening moves bodily away from the door sill and then moves in a linear direction substantially parallel with the plane of the opening in the cover and thus, the door may be arranged to move in shaped guides which define its movement.

The door can be provided with guide elements which are spaced apart across its width and which locate against guides provided on each side of the opening.

In one preferred embodiment the door is raised by a pivoted control arm and this may be balanced.

The control arm can be pivoted to the cover to one side of the door and power operated means can be provided for opening the door.

These power operated means may conveniently comprise a ram connected between the control arm and part of the hood cover.

In any case, the cover can be provided with an inspection door spaced away from the main charging door and which can be used for sampling.

The hood may also include an inclined loading chute which extends beneath the door into the interior of the cover.

The invention can be performed in many ways but one embodiment will now be described by way of example and with reference to the accompanying drawings in which:

FIG. 1 is a front view of a furnace cover according to the present invention FIG. 2 is a cross sectional side view of the cover shown in FIG. 1, and

FIG. 3 is a part plan view of the same construction.

In the drawings the furnace which is static, and is a coreless induction furnace is indicated generally at 1. The cover, indicated generally by reference numeral 2 extends over the upper end of the container 3 in which the metal to be melted is loaded. The cover comprises an outer casing 4 made from steel which is lined with blocks of refractory material 5. A charging door 6 is provided which slides between open and closed positions to close and open an opening indicated by reference numeral 7. The door is also made with a metal outer casing 8 and is lined with a refractory material 9, and in both FIGS. I and 2 is shown in its closed position.

The door is provided with two spaced apart guide elements in the forms of guide pins 10 each of which rests against a guide rail 11. The guide rails 11 are formed from angle material and there is a lower guide lug 12 which has an upper surface 13. Each guide rail 11 has an outer surface 14 which extends substantially vertically apart from a lower guide portion 15.

The upper end of the door is provided with a pair of lugs 16 through which is passed a connection pin 17 on which is located a ring 18 which is in turn connected to. a connector 19 located in another ring 20 connected to a shackle 21. The shackle 21 is carried on a pivoted control arm 22 which is pivoted to the side of the cover by a pivot pin 23 which also passes through a split bracket 24. The end of the control arm 22 remote from the door 6 carries an adjustable balance weight 25 and the arm is operated by a pneumatic double acting ram 26 one end of which is pivoted at 27 to the arm and the other end at 28 to a bracket 29 carried on the wall of the cover.

When the ram is operated it will be seen that the pivoted arm will move to raise the door 6. The guide pins 10 rest against the lower curved portion 15 of the guide rails when the door is'closed and as the door is raised the guide pins cause the door to first move bodily away from the door sill, indicated by reference numeral 30 on FIG. 2, until the guide pins engage the substantially vertically. extending portion 14 of the guide rails 11. Further movement of the arm now causes the door to rise vertically in a linear direction substantially parallel with the plane of the opening 7. The bodily movement away from the opening is accommodated by the connection provided by the shackle 21, rings 20 and 18 and connector 19. When the door is closed, again by operating the ram 26 the lower lug 12 on the guide rails ensures that the pins 10 move into the gap 31 between the surfaces 13 and 15.

Located beneath the door 6 and extending through the opening 7 is a chute 32 which has side walls 33 outside the cover. The lower edge of the door 6 is chamferred at 34 and carries an asbestos sheet 35 so that there is a seal against the surface of the chute 32 when the door is in its closed position. The chute is not shown in FIGS. 1 and 3. When the furnance is to be loaded, the door 6 is raised and material tipped onto the chute 32 so that it slides into the furnace. Apparatus which is suitable for charging such a furnace is described and shown in the Applicants co-pending U.S. application Ser. No. 424,560, filed Dec. 13, 1973, and when this kind of construction is employed the operation of the ram 26 is incorporated into the control system.

Also incorporated in the cover are access ports 34 to allow for the addition of small quantities of alloy material, the introduction of thermo-couple elements for checking the metal temperature and for deslagging the metal bath during operation. These ports 34 are closed by doors 35 which are also made from an outer casing of metal 36 and lined with a refractory material 37.

The portions of the chute 32 which are subject to wear may be lined with wear-resistant or heat-resisting materials (not shown) as appropriate and the selection of the particular type of material will depend upon the ,exact duty which the furnace is to perform.

The chute 32 and the cover 2 are carried on a heavy rolled steel frame indicated at 38 so that this can be raised by means of a crane in order to completely remove the roof to obtain acces to the lining for repair and for servicing of the furnace.

In order to discharge the furnace means for tapping from the bottom (not shown) are provided.

What we claim is:

1. A static non-tipping electric induction furnace comprising a container in which metal to be melted is loaded, said container having an open upper end and a cover which extends over the upper end, said cover having at one side thereof a doorway defined by a door sill, a charging door, mounting means mounting said door for movement between an open position spaced from said door sill and a closed position engaging said door sill. said mounting means including guide means operable during the initial opening movement of the door for moving the door laterally bodily away from the door sill and then in a linear direction substantially parallel to the door sill.

2. A furnace as claimed in claim 1 in which said guide means include shaped guides in which the door moves and which define its movement.

3. A furnace as claimed in claim 2 in which the guide means include guide elements which are spaced apart across the width of the door, and guides are provided on each side of the doorway, said guide elements being in locating contact with said guides.

4. A furnace as claimed in claim 1 in which the door mounting means includes a pivoted control arm for raising the door.

5. A furnace as claimed in claim 4 in which the control arm is pivoted to the cover to one side of the door.

6. A furnace as claimed in claim 4 in which balancing means are attached to the control arm for balancing the effect of the door thereon.

7. A furnace as claimed in claim 1 in which said mounting means include power operated means for opening the door.

8. A furnace as claimed in claim 4 in which said mounting means include power operated means for opening the door.

9. A furnace as claimed in claim 8 in which the power operated means comprise a ram connected between the control arm and part of the cover.

10. A furnace as claimed in claim 1 in which the cover is provided with an inspection door spaced away from the charging door.

11. A furnace as claimed in claim 1 in which the cover includes an inclined loading chute which extends beneath the door into the interior of the cover. 4

12. A furnace as claimed in claim 1 in which the cover has mounting means removably mounting the cover to provide access to the interior of the furnace.

13. A furnace as claimed in claim 1 wherein said cover includes an outer casing lined with refractory material.

14. A static non-tipping electric induction furnace comprising a container in which metal to be melted is loaded, said container having an open upper end and a cover which extends over the upper end, said cover comprising an outer casing lined with refractory material and having at one side thereof a doorway defined by a door sill, a charging door, mounting means mounting said door for movement between an open position spaced from said door sill and a closed position engaging said door sill, said outer casing including support frame means releaseably seated on said container for facilitating the removal of said cover as a unit to provide access to the interior of the furnace. 

1. A static non-tipping electric induction furnace comprising a container in which metal to be melted is loaded, said container having an open upper end and a cover which extends over the upper end, said cover having at one side thereof a doorway defined by a door sill, a charging door, mounting means mounting said door for movement between an open position spaced from said door sill and a closed position engaging said door sill, said mounting means including guide means operable during the initial opening movement of the door for moving the door laterally bodily away from the door sill and then in a linear direction substantially parallel to the door sill.
 2. A furnace as claimed in claim 1 in which said guide means include shaped guides in which the door moves and which define its movement.
 3. A furnace as claimed in claim 2 in which the guide means include guide elements which are spaced apart across the width of the door, and guides are provided on each side of the doorway, said guide elements being in locating contact with said guides.
 4. A furnace as claimed in claim 1 in which the door mounting means includes a pivoted control arm for raising the door.
 5. A furnace as claimed in claim 4 in which the control arm is pivoted to the cover to one side of the door.
 6. A furnace as claimed in claim 4 in which balancing means are attached to the control arm for balancing the effect of the door thereon.
 7. A furnace as claimed in claim 1 in which said mounting means include power operated means for opening the door.
 8. A furnace as claimed in claim 4 in which said mounting means include power operated means for opening the door.
 9. A furnace as claimed in claim 8 in which the power operated means comprise a ram connected between the control arm and part of the cover.
 10. A furnace as claimed in claim 1 in which the cover is provided with an inspection door spaced away from the charging door.
 11. A furnace as claimed in claim 1 in which the cover includes an inclined loading chute which extends beneath the door into the interior of the cover.
 12. A furnace as claimed in claim 1 in which the cover has mounting means removably mounting the cover to provide access to the interior of the furnace.
 13. A furnace as claimed in claim 1 wherein said cover includes an outer casing lined with refractory material.
 14. A static non-tipping electric induction furnace comprising a container in which metal to be melted is loaded, said container having an open upper end and a cover which extends over the upper end, said cover comprising an outer casing lined with refractory material and having at one side thereof a doorway defined by a door sill, a charging door, mounting means mounting said door for movement between an open position spaced from said door sill and a closed position engaging said door sill, said outer casing including support frame means releaseably seated on said container for facilitating the removal of said cover as a unit to provide access to the interior of the furnace. 